In a conventional liquid ejecting device, such as an ink-jet printer, while relatively moving a sheet that serves as a recording medium and ink ejecting mechanisms that serve as liquid ejecting mechanisms in a predetermined direction, ink, which is a liquid, is ejected selectively from nozzles of the ink ejecting mechanisms sequentially arranged in a direction that is substantially perpendicular to the direction of the movement. Accordingly, ink droplets are ejected onto the sheet to form a desired image, whereby characters or the like are printed.
A printer head of the printer includes a head chip. The head chip includes a semiconductor substrate, a plurality of ink ejecting mechanisms sequentially arranged on the semiconductor substrate and having nozzles for ejecting ink, and a driving circuit for dividing the plurality of ink ejecting mechanisms into a plurality of blocks by groups of a predetermined number of units and for dividedly driving the blocks concurrently with reference to a predetermined driving timing signal, thereby causing ink to be ejected from the nozzles.
Such divided driving of a head chip of a printer head is controlled by a controlling scheme referred to as matrix driving. According to the scheme, all the nozzles of a head chip are divided into a plurality of blocks by groups of a predetermined number of units, and the blocks are dividedly driven concurrently, thereby causing ink to be ejected from the nozzles. In this case, the number of driving data lines needed is determined by dividing the total number of nozzles by the predetermined number of nozzles for each group, and the number of signal lines needed for phase signals is the same as the predetermined number of nozzles in each block. Such matrix driving is described, for example, in the specification of U.S. Pat. No. 5,604,519.
Furthermore, the specification of U.S. Pat. No. 5,006,864 describes a scheme in which phase signals to be transmitted to a predetermined number of nozzles in each block are serial-to-parallel converted before the phase signals are transferred.
However, regarding the conventional scheme for divided driving of a head chip of a printer head, according to the first example referred to as matrix driving, for example, when a head chip includes 336 nozzles and the nozzles are divided into a plurality of blocks by groups of 64 units, the number of driving lines is at least six since 336/64=5.25. Since the number of signal lines for phase signals is 64, the total number of control signal lines for divided driving is 70 for one head chip. Thus, the number of control signal lines in an individual head chip is large, so that wiring or bonding inside the head chip is difficult and the size of the chip is large.
In the case of a printer head including a plurality of head chips, for example, a printer head of a line head printer, for example, assuming that the printer head includes 64 head chips, the number of driving data lines is 6×64=384, and the number of signal lines for phase signals is 64, so that the total number of control signal lines for divided driving is 448. Thus, the number of control signal lines for the entire printer head including a plurality of head chips increases, causing increase in wiring space in the printer head and increase in the size of the printer head.
According to the second conventional example in which phase signals are serial-to-parallel converted before the phase signals are transferred, the number of signal lines needed for phase signals is the same as the predetermined number of nozzles in each group. When the predetermined number of nozzles for dividing into a plurality of blocks is increased, the number of control signal lines in an individual head chip increases. Thus, wiring or bonding in the head chip is difficult, and the size of the chip increases.
In view of the situation described above, it is an object of the present invention to deal with the problems described above and to provide a liquid ejecting head, a liquid ejecting device, and a liquid ejecting method that serves to reduce the number of control signal lines for each block in exercising control for dividing a plurality of liquid ejecting mechanisms of a head chip into a plurality of blocks by groups of a predetermined number of units and for dividedly driving the blocks concurrently.